Improvement in preserving wood



- ability of the very best oak, and protected CHARLES KARMRODT AND. NICHOLAS THILMANY, OF BONN P RUS S1 A Letters Patent No. 88,392, dated Mwrch 30, 1869.

IMPROVEMENT IN PRESERVIN WOQD.

The Schedule referred to these Letters Patent and making part of the same.

To all whom it may concern v Be it known that we, Dr. CHARLES KARMRODT and ,NICHOLAS THILMANY, both residents of the town of Bonn, in Prussia, have invented certain new and useful Improvements in Kyauizing Wood; and we do hereby declare that the following is a full and complete description of the same.

The nature of this invention relates to the preservation of wood from decay, by-the impregnation of the same with antiseptic agents,whereby the inherent properties contained in the wood, inducing decay, are non tralized, or destroyed, but leaving its organic structure unimpaired, and its chemical character unchanged.

Sulphate of copper (blue vitriol) has proved itself hitherto one of the most efiicient means for preserving wood coming in permanent contact with water, damp surfaces from decay, frem fungus, from the attacks of worms, and for preventing the havoc caused by the ship-worm, (Teredo new/the) in salt water. 7

On that account, telegraphic posts, railway-sleepers, ship-timbers, 8m, have been impregnated with a solution of sulphate of copper. By this means, they have been able to give to the less expensive sleepers, and poles, prepared from the so-called soft woods, the durthe shiptimbers' from the attacks of the teredo.

Notwithstanding the favorable results which have been attained by impregnating the soft woods with blue vitriol, the fact is,'that the preservation afforded by the imbibed vitriol'only endures as long as the vitriol remains in the wood, and that this only lasted for a period of about twenty years.

It became apparent that the blue vitriol was gradually washed away by water, in view of which, one naturally thought of means to prevent either the chance of the vitriol being washed away, or to reduce this to an immaterial minimum. To accomplish this, many attempts have been made by your petitioners during the last ten years, and of all the means which have been tried, muriate of barytes, (Ghloridumbarit) has proved itself the most efficient, if used in the following manner and proportions, and which requires no permanent nor expensive apparatus, but can be used with safety and ease by any one, and anywhere. This alone is-an improvement on the old method of impregnating with blue vitriol, which required a permanent apparatus, or one with hydraulic pressure, which was ditficult to transport.

Process.

in such a manner that it shall be some two orthree inches higher than the transverse section, so that it forms a dish-like vessel, in which the liquid can be poured. v a

The band'of sheet-lead is fastened to the wood with copper or zinc-covered nails, which can be easily drawn out. Common iron nails must not be used.

'The interstices between the inner side of the vessel formed in this manner, and the section of the tree forming its bottom, which is to be impregnated, should be well plastered with thick clay, so as to allowof no fluid trickling through.

Other suitablemeans may be employed for charging the timber with the compound.

When the logs to be impregnated have been prepared in this manner, water should be poured on them, and that gxadualiy, in the'proportion of two libras (four Prussian pounds) to a cubic foot of wood. This water interpenetrates the wood, removing from it the juices which are easily decomposed, and which hasten its decay, and flows off at the lowerend. The non-observance of this point in the old process, had an injurious result on the object to be obtained.

A solution of rhuriate of barytes is then to be poured on, and thatin the proportion of one and a half to two libras to the cubic foot. The solution should be preparedin such a manner that two Prussian pounds of .muriate of barytes are dissolved in fiftylibras of distilled or rain-water, an operation which is easily performed in a barrel, by stirring with a stick."

When the solutionof muriate of barytes, in the above proportions, is poured overand has penetrated the wood, a solution of blue vitriol is then poured upon it which has been prepared in the same manner, with rain or distilled water. The use of iron or zinc vessels is most carefully to be avoided. To fifty libras of rainwater,

three Prussian pouiids of blue vitriol should be added, and of this solution, two to three libras to the cubic foot should-be poured on the log.

The value of this process is seen in the following explanation. By means of the muriate of barytes, the sulphuric-acid combinations of the wood become fixed, the more easily soluble combinations disappearing. These results'prove the formation of the difficultly-soluble salts of barium. If a solution of blue vitriol is then added, a considerable number of combinations is formed, especially sulphate of barytes, insoluble in water, which cannot be washed away, while the oxide of copper partly enters into a chemical combination with organic substances. Gray-colored spots, containing chloride of copper, appear at length in the wood, proving the successful termination of the operation.

The logs impregnated in this manner should now be removed from their present position, to make room for fresh ones. The rings, or bar-11.3 of lead are then taken 011, and from which any adherent clay is removed They are again used for new logs, as before described or Tcredines nacales.

We obtain a view of the extent'of the work if we calculate that, at the outside, two days are necessary (often only one) for the impregnation of a-single log.

The logs which have been removed from the place of operation, should be so laid that they will dry in a horizontal position in the shade, and can be conveyed as required to the saw-mill. The impregnated logs are then worked up, with well-greased saws, for their destined purposes, for example, sleepers, beams, planks,

&c., and can be cut into any required thickness.

Prepared in this manner, the timber is of greater durability than that prepared solely with blue vitriol,

which may be, to a great extent, washed away, thus rendering null the very means used to preserve the wood.

'The object to be attained is to keep the salts of copper in the wood, thus operating, on the one hand, against decay, and on the other hand, also preventing vegetable parasites, orsmall animals, as wood-worms, p, 850., from effecting their work of devastation.

It is also of no small importance that the newlyformed salts of barium both contribute to the attainment of the last-named advantages, and also that the sulphate-of barytes fills up the pores of the wood, rendering it stronger and more capable of resistance.

Timber which has been so prepared, is'especially suited for buildings under water, railway-sleepers, tele-' 

